Origin and history of spend

mid-14c., dispensen, "to dispose of, deal or divide out," from Old French dispenser "give out" (13c.), from Latin dispensare "disburse, administer, distribute (by weight)," frequentative of dispendere "pay out," from dis- "out" (see dis-) + pendere "to hang, cause to hang; weigh; pay" (from PIE root *(s)pen- "to draw, stretch, spin").

In Medieval Latin, dispendere was used in the ecclesiastical sense of "grant licence to do what is forbidden or omit what is required" (a power of popes, bishops, etc.), and thus acquired a sense of "grant remission from punishment or exemption from law," hence the use of the English verb in the senses "to do away with" (1570s), "do without" (c. 1600). The older sense is preserved in dispensary. Related: Dispensed; dispensing.

"to spend, pay out; to consume by use, spend in using," early 15c., expenden, from Latin expendere "pay out, weigh out money," from ex "out, out of" (see ex-) + pendere "to hang, cause to hang; weigh; pay" (from PIE root *(s)pen- "to draw, stretch, spin"). For the financial sense of the Latin verb, see pound (n.1). Related: Expended; expending.